When Hurricane Irma was barreling up the Atlantic coast of the United States in 2017, Bradley Wilkinson was at Clemson University in South Carolina where he had just started his doctorate studying brown pelicans. As people fled the storm\u2019s path, he realized the GPS trackers on 18 pelicans\u2014intended to measure where they found food\u2014might be able to answer a different question: what would the birds do to survive the storm?<\/p>\n
Studying how birds behave during hurricanes is a tricky task. Usually the aftermath of the storm draws the most attention, like how 2017\u2019s Hurricane Maria killed half of Puerto Rico\u2019s namesake parrots<\/a>. Or how birds end up hundreds of kilometers off course or away from home<\/a>. But advances in technology, including miniature GPS trackers, have made it possible to study animal behavior during these storms \u201cwithout risking the life of the researcher, which is huge,\u201d says Wilkinson.<\/p>\n During three hurricanes\u2014Irma in 2017, and Florence and Michael in 2018\u2014Wilkinson used the GPS tags to learn how the pelicans behaved<\/a>.<\/p>\n He found that during low air pressure and high winds\u2014when the storms were strongest\u2014the birds took refuge in estuaries, or hid behind barrier islands and highway overpasses close to their breeding colonies near Charleston, South Carolina. Hunkering down cost the birds a few days of foraging, but seemed to be a fine-tuned survival technique\u2014the only evidence that a bird might have died was when one GPS tracker went silent during Hurricane Florence.<\/p>\n Kyle Horton, an ornithologist from Colorado State University who was not involved in the study, says that birds have two main strategies to survive a hurricane: they can find some way to weather the storm, or avoid it.<\/p>\n Previous studies suggest some birds, like sparrows, can sense changes in barometric pressure<\/a> and adjust their behavior, says Patrick Jodice, a wildlife biologist at Clemson University and coauthor of the new study. This gives birds time to seek shelter ahead of damaging winds.<\/p>\n In other cases, weather radar shows birds trapped in the storm\u2019s eye<\/a>, possibly a safer place to avoid the dangerous hurricane winds. And frigatebirds, pelagic birds related to pelicans, fly to higher altitudes<\/a> when close to the eye of the storm, presumably to sail through the storm faster.<\/p>\n Horton says the pelicans seem to be relying on both strategies. The pelicans weathered the storm by staying put close to their summer breeding sites along the South Carolina coast, but they also moved behind barrier islands to hide and avoid the storm. An alternative strategy\u2014flying hundreds of kilometers to avoid a storm\u2014could waste a lot of energy.<\/p>\n